


By My Command

by starsinjars



Series: Alpha Twin [2]
Category: Gravity Falls
Genre: F/M, Sibling Incest, Strap-Ons, im so bad at tagging, reverse!pinescest, reverse!verse
Language: English
Status: Completed
Published: 2016-05-26
Updated: 2016-05-26
Packaged: 2018-07-10 08:13:25
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 1,762
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6975031
Author URL: https://archiveofourown.org/users/starsinjars/pseuds/starsinjars
Summary: <blockquote class="userstuff">
              <p>Mabel doesn't like the fact that Dipper has all the control in the sexual part of their relationship, and decides to fix that.</p>
            </blockquote>





	By My Command

**Author's Note:**

> A/N: They're 16. First time writing something like this lolz.

o-o-o-o-o

"I have a problem, dear brother of mine."

Dipper turned to his twin sister Mabel, lowering the voodoo doll he was working on with his telekinesis that came with his half of the pendant. "And whatever would that be, my sweet sister?" he asked, frowning at Mabel's leer. He did not like the little twinkle in his sister's eyes. She was planning something, and that something might not benefit him.

"I was thinking. It's not fair for you to have all the power in this so called relationship of ours," she said as she conjured up a box. Dipper focused on the box, and Mabel grinned as she set it aside and started to remove her collar ribbon and vest.

Dipper smirked back as he loosened the pendant resting on his neck and unbuttoned the top of his shirt. "Really, sister, as if I control anything without you in this twisted bond we call a relationship." He made a reach for his belt.

Dipper paused as his hand started to glow blue. "In this aspect, you do." Mabel narrowed her eyes as she lowered her hand, the blue light fading. She slowly made her way to her brother. "And that does not go well with me."

Dipper raised an eyebrow as Mabel came face to face with him, a soft but sinister smile gracing her lips. "Oh?" he hummed, smirking in reply. "And what are you doing to do about it?"

Mabel snatched his half of the pendant, snapping her fingers.

"What –"

Dipper couldn't finish or take back what Mabel took as he was immediately restrained by ropes and tied down to a chair. He sagged into the ropes, knowing it was futile to fight.

Mabel winked, tossing Dipper's pendant in the air a few times before pocketing it. "I have a few ideas." She climbed to sit on Dipper's lap. Mabel then slid closer to her brother's chest and placed her finger under Dipper's neck, nails slightly etching into his skin as she redirected him to look at her.

"Eyes on me, brother. Only on me," she murmured as she slowly undid Dipper's belt buckle and tugged down his pants. Mabel giggled as she undressed her brother, running her fingers along his now bare chest. She brought her lips to his neck, biting hard.

Taking a deep breath, Dipper tried to focus his thoughts. He'll play this game of his sister's design, but he won't make it easy for her. Seeing that her brother was lost in thought, Mabel's fingers pinched his nipples, making Dipper squirm. "What's in the box?" he asked as he tried to steady his breaths.

"Ah, the box." Mabel smiled innocently, but both knew it was an act. "You'll see soon enough." She unbuttoned her own top to reveal her black lacy bra underneath. Unclipping it from the back, she pushed herself forward so that her breasts would be in front of Dipper's face.

"You know what to do."

With just a moment of hesitation Dipper stuck out his tongue, twirling around one of Mabel's nipples before sucking it gently. He quickly alternated between the left and right, making sure that they were both coated in saliva and perky from the simulation. She sighed as she eased herself closer, keeping the warmth only between the two.

Mabel knew Dipper's hands were twitching, wanting to touch her supple flesh. Not that she could blame him - that was their usual routine, with Dipper in control. Not this time, however. She tightened the ropes, causing Dipper to pull back. He hissed, his mouth making a popping sound as Mabel grabbed him by the hair.

"Not this time, dear brother. Not this time," she murmured. She ran her fingers down Dipper's face and tipped his chin towards her face for a kiss. "This time, we're playing by my rules."

It started sweet, but quickly turned spicy as Mabel bit her brother's lower lip hard enough to draw blood. Dipper moaned, the bloodplay making him lightheaded but horny. "Mabel," he breathed as his sister licked up the blood, but not before some dripped down his chin.

Mabel licked her red lips, grinning before going back for more. Her fingers traced along Dipper's chest, going lower and lower before finally reaching Dipper's hard cock. She palmed it, and didn't miss the hitch in Dipper's breathing.

Mabel grinned as her brother slowly became undone by her design. She softly grinded against it, causing for her brother to squirm. His breaths became unsteady, whole body twitching, and soon enough Dipper was trembling by the slightest touches.

"Funny, how easy it was to rile you up," his sister commented, frowning slightly. "It's almost too easy." She paused.

Dipper smirked at his sister's hesitation. "Isn't this what you wanted, sweet sister?" he asked as Mabel suddenly took hold of his dick and squeezed it tightly. He took a breath. "Me undone by your command?" he asked, voice slightly unsteady.

"No," she replied, twirling her finger around the head. Dipper let out short pants as she slowly began to move her hand up and down the shaft. She bent forward to her brother's ear, placing her hair behind her own ear.

"I want your total surrender."

Mabel pulled back and snapped her fingers. She jumped off her brother's lap as the chair Dipper was sitting in broke to pieces. Dipper fell to the floor, no longer restrained, but all attention was on the box his sister held in her hands.

She tossed the box in the air, suspended by magic, and held her brother down to the ground. She took Dipper's hands and guided them up her legs. Mabel moved Dipper's hands to her panties, and they both groaned after feeling just how wet she was.

"Dipper," Mabel moaned as her brother pulled off her black lace panties and tossed them aside. He grinned as he caressed her inner thighs.

"Mabel," Dipper replied breathlessly, moving his fingers around her clit. He bent his head and soon was licking her wet pussy, eliciting a gasp from his sister.

Dipper ate her out while Mabel stroked his cock, the touches and simulations bringing them closer to the edge.

With a snap of her fingers, Mabel placed a ring on the shaft before she lowered herself onto Dipper's hard cock. He groaned as she sighed, finally feeling full. When she began to move to ride him they moaned, both lost to a rhythm that only they could hear.

Dipper was getting close, Mabel could tell. Not that he could come with the cock ring she placed, but she knew she was getting close as well. He didn't have as much stamina as she did to go for another round, and there was still the present. Mabel was soon hitting her sweet spot. She moved faster, rougher, and was soon riding out her high before she pulled herself off of her still aroused brother.

She quickly regained her composure and smirked. "I think it may be time for your present," she whispered, gesturing with her free hand to summon the box.

Dipper paused, finally about to have his curiosity satisfied. Mabel took her time lifting the lid, slowly reaching inside and pulling out a golden double ended strap-on.

Dipper's eyes widened, then narrowed. He looked… nervous. Mabel snickered. "Afraid, brother of mine?" she whispered as she caressed his face with the object. She didn't wait for a reply as she shoved it in his mouth, planning to use the saliva as lubricant. She lubed up one of her hands with a snap and prodded near Dipper's entrance.

Dipper found his voice as Mabel removed the strap-on from his mouth. "Are you sure you want to do this?" he asked, a slight tremor in his voice that everyone but Mabel would have missed.

Mabel grinned. "So you _are_ afraid." She forced two then three of her lubed fingers inside and scissored them, making Dipper squirm. "Don't you worry, dear brother, I'll be gentle as you are with me." She removed the fingers and moaned as she inserted her end of the strap-on. She placed her hands on Dipper's wrists, readied her position and removed the cock ring before pushing herself inside.

Dipper let out a grunt of pain that trailed off to become a groan, and Mabel waited for him to adjust before moving. She moaned at the feeling of feeling full and filling someone up at the same time. When she began to move, Dipper moaned at the feeling and Mabel quickly found that sweet spot of his. She pounded into him, riding the power high of her actually fucking her brother instead of the other way around.

Dipper found it difficult to think, to breathe, do anything that took his attention away from his sister. Mabel closed her eyes as she slowly started to lose control, and Dipper smirked as she lost her composure completely. As much as he loved fucking her, there was some kind of thrill of her fucking him. Probably because they were breaking yet another taboo about their relationship together. Soon enough he could feel that familiar coil in his belly about to burst and closed his eyes.

Mabel trailed her hand along Dipper's torso and continued to thrust as she kissed her brother's lips. "You look so beautiful under me," Mabel murmured, loving the expression on his face. Dipper kept his eyes shut, biting his lips to keep himself as composed as he could with his sister fucking him. He didn't want to admit that he enjoyed it, but Mabel knew that if she was having this much fun Dipper wasn't as miserable as he'd like her to believe. She could feel herself about to come again and only gave Dipper warning when her thrusts became more erratic.

Mabel moaned as Dipper wrapped his arms around her neck. He pulled her in close, about to capture her lips with a kiss. He froze at the last second and shuddered, pulling his sister tight and close to him as he came. Mabel paused in her thrusts, shuddering as she came as well just a few moments after Dipper.

Mabel grinned as she snapped her fingers to make the strap-on disappear. "That was fun. We should do this again," she murmured softly. They picked each other up from the dirty floor and she handed her brother back his half of the pendant.

Dipper just snatched back his pendant from her in response, but Mabel caught that little twitch of his lips and knew that he agreed.

o-o-o-o-o-o-o-o

 

**Author's Note:**

> A/N: Welp I tried. Thanks for reading!


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